1. Field of the Invention
This invention generally relates to gas-liquid contact systems used in the separation of foreign substances in a gas phase by allowing particulate matter such as solid particles or liquid particles contained in the gas phase to contact with a liquid phase to be trapped or dissolved the particles therein. Specifically, this invention is concerned with a gas-liquid contact system utilized for purifying and defecating a gas phase by trapping and dissolving foreign substances in the liquid phase to separate from the gas phase. In the gas-liquid contact system, the foreign substances in the gas phase including minute solid particles such as burned ash, unburned carbon, silicon dioxides, zinc oxides, aluminum oxides, and silicon nitride are allowed to contact with the liquid phase so that the foreign substances contained in the substances are trapped in the liquid phase and separated from the gas phase, or the foreign substances contained in the gas phase including entrained mist such as a droplet or sulfuric acid are allowed to contact with the liquid phase so that the foreign substances in the substances are trapped and dissolved in the liquid phase, thereby purifying and defecating the gas phase.
2. Description of the Related Art
Known related-art gas-liquid systems utilized for the separation of foreign substances from a gas phase include gravitational, inertial, centrifugal force, cleaning, filtered, electric, and sonic types.
The gravitational, inertial, and centrifugal-forcing gas-liquid systems usually exhibit low separation efficiency in separating minute solid particles from the gas, each having a diameter of 1 μm or less. If separating the minute solid particles, in particular, from a hydrated gas, a significant pressure loss or clogging may be observed in such systems due to the accretion of the minute solid particles. These types of systems generally require repair and maintenance cost accordingly.
As an example of the cleaning gas-liquid system, a venturi scrubber can be given; however, the venturi scrubber generally exhibits pressure drop of 300 to 1200 mmH20 (3 to 12 kPa), which results in high power expenses.
As an example of the filtering system having filter fabric, a bag filter can be given; however, when filtering solid particles having high adhesive properties or hydrated gases with the bag filter, the filter fabric of the filtering system tends to be clogged with these particles in a short time, thereby resulting in high repair and maintenance cost.
A typical electric dust collecting system consumes a high voltage power supply, which requires high electric power expenses. In addition, the maintenance cost needs preparing for clearing or collecting the attached solid particles from a dust collecting electrode.
In view of the aforementioned factors, Japanese Unexamined Patent Application Publication No. 2004-181437 discloses a separator for foreign substances (also called a “gas-liquid contact system”) having a static fluid mixer arranged approximately perpendicular to the ground in a longitudinal direction, a first supplier supplying liquid from an upper end to an inside of the static fluid mixer, and a second supplier supplying gas containing foreign substances from a lower end to the inside of the static fluid mixer. The static fluid mixer includes a passage tube through which a fluid is caused to flow, and at least one mixing element having at least one spiral blade placed in the passage tube, and the passage tube and the mixing element are continuously arranged in the longitudinal direction. In the static fluid mixer, liquid flows downwardly while gas flows upwardly, thereby causing the liquid and gas to be mutually in contact.